When a patient suffers from orthopedic injuries, deformities or degenerative diseases, it is sometimes necessary to insert implants into the patient's body to stabilize an internal structure, promote healing, or relieve pain. In the area of spinal surgery, for example, a common procedure involves the use of screws or hooks joined by a connecting brace in order to secure bones. Once the brace is placed in the patient's body, the brace must be firmly secured to the screws or hooks in order to provide a stable construct which effectively immobilizes a corresponding portion of the spine. Then, a set screw or locking element presses against the brace to secure the brace to the hooks or screws.
When surgery is performed, the surgeon often needs to distract bone by pulling it away from the work site or compress bone to pull it together if broken, as an example. In the area of spinal surgery, a surgeon may approach the spinal column of a patient from a posterior position, and force is applied in order to move implants along a rod in order to distract or compress bone or implants into the most favorable position. Force also may be applied to distract or compress prior to insertion of a rod.
In the past, two separate devices have been used to perform compression and distraction. As an example, U.S. Pat. No. 6,716,218 issued to Holmes et al., teaches a device that performs distraction. If the surgeon desires to perform compression, another device would be required. Additionally, this type of compression or distraction device is not minimally invasive. Rather, a large incision is required to use this device. Thus, during a procedure, a surgeon has to switch devices depending on whether compression or distraction is desired. This need for switching devices may increase the amount of time required to perform the procedure, and thus may result in a longer recovery time for the patient.
Alternatively, certain devices are available that allow for parts to be substituted, or changed out, in order to perform distraction or compression. As shown in U.S. Pat. No. 6,551,316. (“the '316 patent”), for example, a device is provided having two sets of handles that can be selectively interconnected on an assembly. One set of handles would be affixed to a jaw section when compression is needed. This first set of handles may be substituted with the second set of handles configured to be used for distraction as desired. If the surgeon desires to perform compression, one set of handles is attached to the assembly, and if distraction is desired, then the set of handles for compression must be removed and replaced with the set of handles for use in distraction. Accordingly, it takes time for the surgeon to replace the handles during the procedure. Further, the surgeon must remove the jaw section of the device from the patient's body if he/she decides to employ a different technique, causing the length of the surgical procedure to increase. Additionally, the handles of the device described in the '316 patent that the surgeon manipulates are relatively large, causing the device to be top-heavy due to the size of the handles. The surgeon's hand would likely cover approximately half to two-thirds of the handle portion in order to steady the device during the procedure. Thus, the device cannot be left unattended inside the patient. Also, the device of the '316 patent is not minimally invasive, but instead requires a large incision to insert the jaws of the device. Even if the surgical procedure itself is minimally invasive, use of the non-minimally invasive '316 patent device would effectively block the surgeon's ability to visualize the operative site and to conduct the operation in a minimally invasive fashion.